Triangulation laser scanners for capturing surface coordinates of a workpiece to be measured are well known from the related art. The latest triangulation laser scanners use a CMOS sensor chip, which makes it possible for image files to be captured in so-called HDR formats. With the triangulation laser scanners, to evaluate the surface coordinates of a workpiece to be measured, the lateral deviation of the image position of a laser line with respect to its nominal position on the sensor chip is brought into a relationship with the distance of the triangulation laser scanner from the surface of the workpiece to be measured by classic triangulation. As a consequence, with triangulation laser scanners, only a lateral X and Y position of a bright pixel on the sensor chip is of importance. In particular, in the case of triangulation laser scanners with a Scheimpflug arrangement of the laser light plane, the lens plane of the imaging system, and the receiver plane of the CMOS sensor chip in relation to one another, only those surface points of the workpiece to be measured that are located in the laser light plane are projected as sharp images onto the CMOS sensor. All other surface points of the workpiece to be measured are not projected as an image at all. Consequently, with triangulation laser sensors with a Scheimpflug arrangement, only those X and Y positions that correspond to a point of intersection of the laser light plane with a surface point of the workpiece can be captured as two-dimensional data on the sensor chip.
Apart from such triangulation laser scanners, all possible forms of barcode readers, starting from the barcode reading pen to the camera scanner or mobile phone scanner, are know from the related art. Furthermore, the use of a barcode scanner for volume measurement is known from U.S. Pat. No. 6,260,001 B1. The simple barcode readers may just read one-dimensional barcodes, whereas camera or mobile phone scanners even read two-dimensional barcodes. In this respect, obtained items of pixel information or image files of the readers are evaluated by known evaluation methods for barcode recognition or by known methods of image processing. Apart from the lateral X and Y position of a bright image point, the brightness of the image point on the sensor chip of a barcode reader is also of importance for the evaluation of the barcode. For this reason, barcode evaluations in the related art generally depend on complete image files of the sensor chip, in which all pixels of the sensor area of the sensor chip are read out, and the barcode evaluations in the related art cannot use the typical data of a triangulation laser scanner, as further explained below.
Apart from triangulation laser scanners and barcode readers, cameras, in particular color cameras, are also known for capturing a texture of surfaces in 3D coordinate measurements, see U.S. Pat. No. 8,284,240 B2. The two-dimensional data of such color cameras are generally used to make the obtained 3D data correspond to the associated surface texture in the visualization with respect to the user. The surface texture may constitute here just the color of the surface. It is also possible, however, to detect other properties of the surfaces, such as the roughness of the surface texture. In this regard, it is possible for example to take into account for visualization of smooth glass surfaces of the workpiece be measured to the user, that the associated 3D data of the glass surface are displayed in blue color. In the same way as barcode readers for the detection of two-dimensional barcodes, such cameras for capturing the texture of surfaces depend on the two-dimensional sensor chip receiving a complete two-dimensional data record of the sensor area that can be investigated for the presence of barcode information and/or for the presence of texture information on the basis of its brightness or color information content.
In contrast to cameras for texture detection and in contrast to barcode readers for capturing 3D coordinates of surfaces, the sensor chips of triangulation laser scanners are read out with high clock frequencies to make a rapid scanning of the surfaces possible. In this respect, a reduction of the amount of data is desirable. To reduce the amount of data, generally only the data with respect to the lateral X, Y position of the bright image points and a quality criterion for each of the bright image points is transferred. Consequently, only the “bright” fraction of the two-dimensional data record of the overall sensor area is used. The quality criterion serves in this case for marking a measured value or a measuring point as valid or invalid for an evaluation. As already mentioned earlier, in particular when using triangulation laser scanners with a Scheimpflug arrangement, only such reduced data are captured, since only the points within the laser light plane are projected as a sharp image. This reduced amount of data is far less extensive than the complete two-dimensional data record of a sensor image, as a result of which this reduced data record can also be transferred with high clock rates. However, the data transferred up until now of triangulation laser scanners in the related art cannot be evaluated by barcode evaluations and/or texture evaluations of the related art with regard to the presence of barcode information and/or with regard to the presence of texture information because the lateral X, Y position data of the captured laser lines do not contain corresponding items of information.